Raspberry Pi SBC LAN Phone to LAN Phone Traffic NOT Local

One of the touted benefits of using the 3CX RPi SBC is to keep LAN phone extension to LAN phone extension network traffic on the LAN thereby conveniently avoiding routing the heavy and latency sensitive RTP packets to and from the 3CX server which helps avoid chewing up precious Internet bandwidth and provides terrific audio call quality for in-office calls.

In the following video, there are four phones on the LAN calling another - x148 -> x145 and x141 -> x119. But, note how every phone has a leg to the RPi. That shouldn't be. The traffic should be directly between the phones without transiting through the RPi, and certainly not going to the 3CX Server only to come right back to the LAN. BTW, the 90K per phone network traffic is not SIP, it's nearly all RTP as displayed in the pie graph in the pop-up windows.